Constant level liquid supply means

ABSTRACT

A liquid supply means are disclosed for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed. The supply arrangement includes a base assembly having a bore communicating with the user assembly and socket means communicating with the bore. The liquid supply is contained in a reservoir assembly having outlet means. The reservoir assembly is adapted for disposal in the base assembly socket means with the outlet means in communication with the socket means and user assembly. The desired constant liquid level in the user assembly is established by the reservoir assembly outlet means. Vent means are provided for the reservoir assembly and communicates with the outlet means to vent the reservoir assembly through the outlet means to thereby restore the desired liquid level as liquid is consumed by the user assembly. The reservoir and base assemblies are each provided with valve means adapted to close when the reservoir assembly is separated from the base assembly. The respective valve means are adapted to open in response to a reassembly of the reservoir assembly into the base assembly socket means.

United States Patent [72] Inventor Donald G. Gruett Primary Examiner-M. Cary Nelson Manltowoc, Wis.

Assistant Examiner- David R. Matthews Attorney-Andrus, Sceales, Starke & Sawall ABSTRACT: A liquid supply means are disclosed for maintaining a relatively constant level of liquid in a user assembly mw mum 9cm 1 l M0 926R" 2 n am 110M de N wm n tl g WCP M na AFPA ill] 253 HUN.

wherein the liquid is consumed. The supply arrangement includes a base assembly having a bore communicating with the [54] CONSTANT LEVEL LIQUID SUPPLY MEANS user assembly and socket means communicating with the 17 Chm-7 Drawing 8x bore. The liquid supply is contained in a reservoir assembly having outlet means. The reservoir assembly is adapted for disposal in the base assembly socket means with the outlet l l4 2. 1/ 184/103 R means in communication with the socket means and user as- [51] Int. G05d 9/02 1- desired constant i i level in the user assembly [50] Field 0! 137/453, is established by the reservoir assembly outlet means v 6l4'ozizslll49'3i 149-6? H348, means are provided for the reservoir assembly and commu- 35 354; 84/103 nicates with the outlet means to vent the reservoir assembly through the outlet means to thereby restore the desired liquid level as liquid is consumed by the user assembly, The reservoir [56] References Cited UNITED STATES PATENTS 8/1933 Armantrout et a1.

11/1945 Schwabe, Jr........

adapted to open in response to a reassembly of the reservoir 184/103 assembly into the base assembly socket means.

34 o 1 am 1114 8 1 2,672,951 3/1954 Bogert......... 2,760,599 8/1956 Sunden 8 II II II II I t 9 T a I Q m e l 54 0 t 5 3 v p l 5 1O i n mvfll I! 2 i M frlll gfllv h 1 w i .AQI. I .itniniLiiw-LI.itinttmwwtwlvnululss. n 111111 i .lllllell| .lle s aAmcmmwmm, I; 7L z H 7 3 e c n 4 I PATEN-TEI] JUL 6 I971 SHEET 1 [IF 2 INVENTOR. DONALD G. GRUETT QZZ, 2264M Attorneys PATENIEU JUL 6197! 3590,857

SHEET 2 0F 2 FIG 7 INVENTQR DONALD G GRUETT BY 7 I z Attor ys This invention relates to a constant-level liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed.

In constant-level liquid supply means of the general type herein disclosed accurate level control has been difficult to achieve, especially for heavier liquids, and as a consequence the liquid level can vary greatly. Then, too, for such devices the rate of recovery of the desired liquid level is frequently slow. When it comes time to replenish the liquid supply, that task tends to be messy. Especially is this so when the supply means is a lubricator for bearings, gear boxes, pump housings, and the like in which case the liquid is an oil lubricant. It is generally an object of this invention to provide a constantlevel liquid supply means which can be accurately controlled within narrow limits and will provide a relatively rapid rate of recovery of liquid level. The supply means of this invention is further characterized by its compactness,'a relatively high surge level, ease of refilling and an ease for liquid level adjustment.

SUMMARY OF THE INVENTION The invention is directed to liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is being consumed. The supply means includes a base assembly having a bore communicating with the user assembly and socket means communicating with the bore. The liquid supply is contained in a reservoir assembly having outlet means. The reservoir assembly is adapted for disposal in the socket means with the outlet means in communication with the socket means and hence with the user assembly and with the outlet means establishing the desired constant liquid level in the user assembly. Vent means are provided for the'reservoir assembly and communicates with the outlet means to vent the reservoir assembly through the outlet means to thereby restore the desired liquid level as liquid is consumed by the user assembly. The reservoir assembly and base assembly are each provided with valve means adapted to close when the reservoir assembly is removed from the base assembly socket means and thereby prevent liquid flow from the user assembly and the reservoir assembly. The respective valve means are adapted to open in response to a reassembly of the reservoir assembly into the base assembly socket means.

DESCRIPTION OF DRAWING FIGURES The drawings furnished herewith illustrate the best mode presently contemplated and set forth hereinafter for carrying out the invention.

In the drawings:

FIG. 1 is a sectional view in elevation showing a constant level lubricator or oiler embodying the invention;

FIG. 2 is an enlarged partial sectional view in elevation showing the reservoir assembly of the lubricator of FIG. 1.

FIG. 3 is a partial sectional view in elevation of the base fitting assemblyof the lubricator of FIG. 1 and shows the valve therein closed to keep the oil'in the user assembly when the reservoir assembly is removed-therefrom;

FIG. 4 is an enlarged detail view in section showing the vent tube for the lubricator of FIG. I and illustrating the mode of adjustment for the oil level with the adjusting means shown in a givenposition and in phantom showing the adjusting means in the minimum position;

FIG. 5 is a detail view showing a portion of the reservoir venting arrangement for the lubricator of FIG. 1 whereby the level of the oil is maintained within relatively narrow limits and in phantom lines generally illustrates diagrammatically the level at which air will bubble up into the reservoir of the oiler;

FIG. 6 is an elevational view partially in section showing a filter fitting assembled with the venting means of the oiler of FIG. I; and

FIG. 7 is an elevational view partially in section showing an embodiment of the invention wherein the venting means of the lubricator is connected to the user assembly so that the pressure in the user assembly and the reservoir is equalized.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS The constant-level liquid supply means of this invention finds application in lubricators, humidifiers, and all manner of moisturizing installations wherein a relatively constant level of liquid is desired or must be maintained. With reference to the drawings, however, the invention is herein described as applied to a constant-level lubricator or oiler 1.

The lubricator or oiler 1 generally comprises a reservoir assembly 2 engaged within a base fitting assembly 3. The base fitting assembly 3 is adapted for connection to the housing 4 of an oil lubricant user assembly 5, such as the antifriction bearing 6 shown in FIG. I for rotatably supporting the shaft 7 within the housing. The lubricator or oiler 2 is adapted to maintain the oil lubricant in the housing 4 at a desired generally constant level to assure the proper functioning of the bearing 6.

The reservoir assembly 2 includes the reservoir 8 which may be a transparent plastic container of any desired size for containing a supply of oil lubricant. The reservoir 8 is provided with a neck 9 which is threaded externally and terminates with the mouth 10. The mouth 10 is closed by a cover assembly 11 including the cover 12 which is threaded internally to threadedly engage over the neck 9. In the assembled oiler 1, the-mouth 10 of the reservoir and its cover assembly 11 are inverted or disposed downwardly as generally shown in FIG. 1.

The cover assembly 11 of the reservoir assembly 2 includes the tubular body member 13 which is stepped externally adjacent the upper end thereof to provide the annular shoulder 14 and a reduced end portion 15. The end portion 15 of member 13 is threaded externally and adapted to extend through the opening 16 in the cover 12 and project into the reservoir 8 where the nut 17 is engaged thereon. The nut 17 is adapted to draw the annular shoulder 14 up tight against the outside of the cover 12 to securely clamp the body member 13 to the cover.

The bore of tubular body member 13 is stepped to provide an annular shoulder 18 which faces upwardly into the reservoir 8 intermediate a smaller bore portion 19 adjacent to the lower end of the member and the enlarged bore portion 20 which opens into the reservoir. A guide tube 21 is fixedly secured within the smaller bore portion 29of body member 13 and extends upwardly into the reservoir 8 in spaced relation from the wall of the enlarged 'bore portion 20. The guide tube 21 is provided with a pair of diametrically opposed, relatively narrow rectangular outlets or slots 22 which extend upwardlyfrom shoulder 18 of the body member 13 to place the enlarged bore portion 20 and the reservoir 8 in communication with the bore23 of the guide tube.

A gate tube or valve member 24 is slidably disposed on the guide tube 21 and extends upwardly into the reservoir 8. The gate tube 24 provides an extension of the guide tube bore 23 which is closed by the plug 25 at the upper end of the gate tube. A helical spring 26 is disposedaround the gate tube 24 in the enlarged bore portion 20 and extends between an annular radial outward projection 27 on the lower end of the gate tube and an annular radial flange .28 projecting inwardly over the end of the body member 13 from the nut 17. The spring 26 is adapted to bias the gate tube 24 downwardly toward the shoulder 18 of the body member 13, and upon removal of the reservoir assembly 2 fromthe base fitting assembly 3 the gate tube 24 is biased downwardly against the shoulder 18 to close the diametrically opposed slots 22 of the guide tube 21 as generally shown in FIG. 2.

The base fitting assembly 3 generally comprises a blocklike body member 29 having a cylindrical socket or cavity 30 opening upwardly to receive the tubular body member 13 of the reservoir assembly 2. A threaded bore 31 extends from the bottom of the body member 29 to the bottom of cavity 30 and is generally coaxial with the cavity. The bore 31 is adapted to threadedly receive the vent fitting 32 which has a stepped bore with the enlarged bore portion 33 opening downwardly to the atmosphere. A vent tube 34 is fixedly secured in the smaller bore portion 35 of the vent fitting 32 and extends upwardly coaxially through the cavity 30 and projects above the body member 29. The upper end of the vent tube 34 is threaded internally and adapted to receive the adjusting screw 36, the purpose of which will be more fully described hereinafter. The adjusting screw 36 may be threadedly engaged within the vent tube 34 of any desired amount over its length and may then be secured relative to the tube 34 by the locknut 37. As shown in FIGS. 1 and 4 the vent tube 34 is provided with a plurality of openings 38 generally immediately beneath the fully engaged position of the adjusting screw 36 to place the bore 39 of the vent tube in communication with the bore 23 of the assembled oiler l. The vent tube 34 is cut on a bias to provide an enlarged mouth 40 at the lower end thereof which projects downwardly into the bore 33 of the vent fitting 32 for reasons hereinafter explained.

The body member 29 is further provided with a generally horizontal stepped bore 41 which extends generally radially from cavity 30 to one side of member 29. A check valve 42 controls the flow from the bore 41 into the cavity 30 with the valve seat 43 being disposed immediately adjacent to the cavity. The valve ball 44 of valve 42 is adapted to rest on the seat 43 to close the valve with a portion of the ball projecting into the cavity 30. The valve ball 44 is biased toward the valve seat 43 by the helical spring 45 disposed in bore 41 between the valve ball and the retainer ring 46. The bore 41 is threaded adjacent to the side opening from the body member 29 and is adapted for coupling to a corresponding bore 47 on a user assembly by one or more coupling elements 48.

The cylindrical cavity 30 in the base fitting assembly 3 is adapted to slidably receive the lower reduced diameter portion 49 of the tubular body member 13 of the reservoir assembly 2. Insertion of the portion 49 into cavity 30 is complete when the adjacent annular radial shoulder 50 seats against the upper surface of the body member 29 and the one or more spring clips 51 carried by the body member 29 engage within the circumferential recess 52 provided on the body member 13 intermediate the spaced shoulders 14 and 50. The tubular body member 13 of the reservoir assembly 2 has a radially extending annular projection 53 adjacent to the lower end thereof which has a diameter corresponding generally to that of the lower portion 49. When the insertion of portion 49 of body member 13 into base fitting cavity 30 is complete, the projection 53 will have engaged and unseated the valve ball 44 to place the horizontal bore 41 of the base fitting assembly 3 into flow communication with the cavity. A sealing O-ring 54 is provided in the circumferential recess 55 in the lower portion 49 of body member 13 above the projection 53 to effect a seal between the body member and the wall of cavity 30.

When it is desired to fill or refill the reservoir 8 with oil lubricant, removal of the assembly 2 from cavity 30 of the base fitting assembly 3 is accomplished with a modest upward pull such as will cause the one or more spring clips 51 to deflect from the recess 52. During periods of removal of the reservoir assembly 2 from the base fitting assembly 3, the lubricant in the housing 4 of the user assembly 5 is trapped and retained therein by closure of the check valve 42 in the bore 41. And loss of lubricant from the reservoir assembly 2 is substantially prevented as the helical spring 26 biases the gate tube 24 downwardly against the shoulder 18 to close the slots 22 in the guide tube 21. The provision for removal of the assembly 2 to fill the reservoir 8, permits the filling task to be performed conveniently at a place and in a position of ones choosing so as to avoid spillage and possible accident.

Filling of the reservoir 8 is accomplished by inversion of the assembly 2 from its in service" position shown in FIG. 1 so that the assembly can rest on the reservoir surface 56. Removal of the cover assembly 11 subsequent to inversion exposes a relatively wide mouth 10 so that the task of filling may be rapid with minimum risk of spillage. If desired, the reservoir 8 may carry a full" indicator which will take into account the fluid displaced by the inwardly projecting gate tube 24 so as to avoid possible overflow when the cover assembly 1 1 is resecured onto the neck 9 of the reservoir.

When the reservoir assembly 2 is returned to its "in service" mounting on the base fitting assembly 3, the vent tube 34 projecting upwardly from cavity 30 is received in the bore 23 of the guide tube 21 and gate tube 24. As the tubular body member 13 of the reservoir assembly 2 is seated on the base fitting assembly 3, relative movement takes place between the gate tube 24 and the guide tube 21 to open at least some portion of the guide tube outlets or slots 22 as the gate tube end plug 25 engages and is lifted by the adjusting screw 36 at the upper end of the vent tube 34, even in the fully engaged position of the adjusting screw as generally shown in FIG. 1 and in phantom lines in FIG. 4. When the reservoir assembly 2 is fully seated in the base fitting cavity 30, the slots 22 will be open in accordance with the setting of the adjusting screw 36 and the ball 44 will have been unseated to open the valve 42 in the horizontal bore 41 to place the oil lubricant contents of the reservoir 8 in communication with the housing 4 of the user assembly 5.

As a possible alternative to the practice of individual refilling of reservoir 8 at or adjacent to the particular oiler installation, extra" reservoir assemblies 2 corresponding in size and number to the oiler assemblies 1 in service or some multiple thereof, may be refilled at a designated station for filling. The filled extra reservoir assemblies 2 are then simply exchanged in situ for the like assemblies in service which are in turn refilled at the designated station for further subsequent replacement or exchange.

In service, operation of the oiler 1 is based on the liquid seal principle with the level of oil lubricant in the user assembly 5 being determined by the height of slot opening as generally established by the lower edge of the gate tube or valve member 24. As generally shown in FIG. 5, the level of the oil lubricant is in fact slightly beneath the lower edge of gate tube 24 due to the sealing action of the liquid surface tension. As the lubricant is consumed in the user assembly 5 and the liquid level drops, the sealing effect due to surface tension is weakened and subsequently broken allowing the venting air in bore 23 above the level of the lubricant to enter the reservoir 8 and thereby release the oil lubricant until a seal is reestablished with the lower edge of the gate tube 24 and the proper level of lubricant in the user assembly is restored. The guide tube slots 22 controlling the venting air are relatively narrow and are believed to control the size of the air bubbles entering the reservoir 8 as diagrammatically illustrated in FIG. 5 wherein a representation of an air bubble is shown in phantom lines in the slot. It has been found that with a slot width between seven sixty-fourths and five thirty-seconds inch the oil lubricant level can be maintained within relatively narrow limits and that recovery of the proper level is relatively rapid.

To accommodate varying installation requirements of different user assemblies 5, the height of the exposed openings of slots 22 may be varied to establish the desired or optimum oil lubricant level suited to a particular user assembly. This is accomplished by varying the height of the gate tube 24 relative to the guide tube 21 as provided for by the adjusting screw 36 at the upper end of the vent tube 34. FIG. 4 generally shows a given position of adjusting screw engagement to provide corresponding exposure of the slots 22 beneath the lower edge of gate tube 24, and in phantom lines shows minimum opening or exposure of the slots. Minimum slot exposure is also indicated in FIG. 1 of the drawings to provide the proper lubricant level suited to the user assembly 5.

In the course of operation of certain user assemblies 5, a considerable amount of oil lubricant is carried to the upper portion of the user assembly housing 4. When the user assembly 5 is shutdown, this oil drains to the lower portion of the housing 4 and causes oil to surge back to the lower portion of 5 the housing 4 and causes oil to surge back to the reservoir 8 generally to the extent of the drain off. Until the pressure in the reservoir 8 reaches atmospheric pressure, the reservoir will accept such surge oil. If, however, the amount of surge oil is more than the reservoir 8 can accept, it will rise around the vent tube 34 in the bore 23. In the vent the surge level, as established by the vent openings 38, is exceeded, the surge oil may enter the vent tube and threaten a siphoning action which could remove substantially all the oil in the reservoir 8 and the user assembly 5. The oiler l of this invention is characterized by a relatively high surge level because the air vent arrangement is disposed interiorly relative to the reservoir assembly 2 and therefore the vent openings 38 in the vent tube 34 may be placed relatively high with respect to the oil level. As a further precaution against a possible siphoning action, the vent tube 34 is bias cut at the lower end to provide an enlarged mouth 40 for the vent tube bore 39 so that air is afforded a better opportunity to enter the bore and break up any threatened siphoning action. 7

Because the venting arrangement of this invention opens downwardly, considerable protection is afforded against entry of dirt and dust. In an unusually dusty an/or dirty environment, however, an air filter unit 57 may be threadedly received in the vent fitting 32 to protect the oil supply from deleterious matter as generally shown in FIG. 6.

F IG. 7 shows a further arrangement for protecting the oil supply from deleterious matter in the environment. According to FIG. 7, the housing 58 of the, user assembly 59 is provided with a vent opening 60 which is connected through an equalizer tube 61 to the vent fitting 32 of the base fitting assembly 62. With the equalizer tube arrangement the desired level of oil lubricant in the user assembly 59 is maintained even if excessive back pressure or a vacuum condition develops in the user assembly. Thus, the equalizer tube 61 assures a static balance of pressure between the user assembly 59 and the oiler 63.

The embodiment of FIG. 7 further illustrates an oiler assembly 63 wherein the upper portion of the wall of cavity 64 in the base fitting assembly 62 is threaded and complementary threads are provided on the body member 65 of the reservoir assembly 66 to provide for threaded engagement between the reservoir assembly and the base fitting assembly. Operation of the oiler assembly 63 is generally similar to that of the oiler assembly l ofFlG. l.

The oiler construction of this invention providing for a venting arrangement interiorly of the reservoir results in a compact unit assembly having a relatively high surge level. The provision for liquid level adjustment makes the unit assembly more adaptable for a wide variety of installations. Provisions for removal of the reservoir assembly for easy refilling, avoids a possible mess and promotes safety. The assemblies 1 and 63 are adapted for use with a wide variety of fluids ranging from water or lighter spirits to relatively heavy oils.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

lclaim:

1. ln liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed, a base assembly having a bore communicating with the user assembly, socket means associated with the base assembly and communicating with the bore in said assembly, a reservoir assembly containing the liquid supply and having outlet means, said reservoir assembly being adapted for disposal in the socket means with the outlet means in communication with said socket means and hence with said user assembly, said reservoir assembly outlet means establishing the desired constant liquid level in said user assembly, vent means in communication with said reservoir assembly outlet means to vent the reservoir assembly through said outlet means to thereby restore the desired liquid level as liquid is consumed by the user assembly, and valve means for the reservoir assembly and the base assembly, the respective valve means being adapted to close when the reservoir assembly is removed from the socket means to prevent liquid flow from the reservoir assembly and user assembly and said respective valve means being adapted to open in response to a reassembly of the reservoir assembly into the socket means.

2. The invention as set forth in claim 1 wherein the valve means for the base assembly is a ball check valve disposed in the bore of the base assembly with the valve seat adjacent to the socket means, the ball upon closure of the check valve being adapted to rest on the valve seat and project into the socket means, said reservoir assembly including means engageable with the ball of the check valve to unseat the ball and open the valve when the reservoir assembly is disposed in the socket means.

3. The invention as set forth in claim 1 wherein the socket means is disposed in the base assembly and the base assembly bore is generally horizontal and extends radially from said socket means.

4. The invention as set forth in claim 3 wherein the valve means is disposed in the base assembly and the base assembly bore is generally horizontal and extends radially from said socket means.

5. The invention as set forth in claim 3 wherein the vent means comprises a generally vertically disposed tubular member secured to the base assembly and opening downwardly therefrom and extending upwardly generally coaxially through the socket means.

6. The invention as set forth in claim 5 wherein the lower end of the venting tubular member is cut on a bias to provide an enlarged opening.

7. The invention as set forth in claim 1 wherein the reservoir assembly includes a cover assembly which is removable to fill the reservoir assembly.

8. The invention as set forth in claim 7 wherein the cover assembly for the reservoir assembly includes a body member of which at least the lower portion is adapted to be received within the socket means associated with the base assembly.

9. The invention as set forth in claim 8 wherein the body member is slidably disposed within the socket means.

10. The invention as set forth in claim 8 wherein the body member is threadedly engaged within the socket means.

11. in liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed, a base assembly having a bore communicating with the user assembly, socket means in the base assembly and communicating with the bore in said assembly, a reservoir assembly containing the liquid supply, a removable cover assembly on said reservoir assembly, a body member carried by the cover assembly with at least the lower portion of said body member being adapted for disposal within the base assembly socket means, said body member being provided with a stepped bore with the smaller bore portion adjacent to the lower end thereof and an enlarged upper bore portion opening into the reservoir assembly, a tubular member secured in the smaller bore portion of the body member and extending upwardly through the enlarged bore portion, the bore of said tubular member communicating with said socket means and hence with the user assembly when the reservoir assembly is disposed in the socket means, outlet means in said tubular member placing the bore thereof in communication with the enlarged bore portion of the body member and hence with the interior of the reservoir assembly, a tubular valve member closed at the upper end thereof and slidably disposed on said tubular member for movement between an outlet means open position and an outlet means closure position, vent means in communication with said reservoir assembly outlet means for venting the reservoir assembly, abutment means associated with the base assembly and extending through the bore of the reservoir assembly tubular member and engaged by the closed end of the valve member to maintain the valve member in the outlet means open position when the reservoir assembly is disposed in the base assembly socket means, and means to bias the valve member downwardly to the outlet means closure position when the reservoir assembly is removed from the base assembly socket means.

12. The invention as set forth in claim 11 wherein an annular shoulder is provided intermediate the stepped bore portions of the body member, said shoulder being engageable by the valve member in the outlet means closure position of said member.

13. The invention as set forth in claim 12 wherein the tubular member outlet means comprises a plurality of circumferentially spaced generally rectangular slots which extend upwardly from the annular shoulder in the bore of said body member.

14. The invention as set forth in claim 13 wherein the rectangular slots are of a width generally of an order of oneeighth inch to regulate the size of the venting air bubbles entering the reservoir assembly as liquid is consumed in the user assembly to thereby maintain the liquid level in the user assembly generally constant within relatively narrow limits.

15. The invention as set forth in claim 13 wherein the vent means comprise a vertical tube secured to the base assembly and which opens downwardly beneath the base assembly, said vent tube extending upwardly generally coaxially through said socket means and the bore of the tubular member, the upper end of said vent tube forming the abutment means engaged by the closed end of the valve member when the reservoir assembly is disposed in the base assembly socket means to maintain the valve member in spaced relation from the body member shoulder and thereby open at least some portion of the rectangular outlet slots.

16. The invention as set forth in claim 15 wherein a threaded member is engageable within the upper end of the vent tube to form the abutment means engageable by the closed end of the valve member when the reservoir assembly is disposed in the base assembly socket means, said threaded member being vertically adjustable to vary the outlet slot openings and correspondingly vary the liquid level in the user assembly.

17. The invention as set forth in claim 11 wherein check valve means are disposed in the bore of the base assembly and is adapted to close to preclude liquid flow from the user assembly when the reservoir assembly is removed from the base assembly socket means, said check valve means being adapted to open in response to a reassembly of the reservoir assembly into the socket means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3.590 857 Dated July 6, 1971 Inventor(s) Donald G. Gruett It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 22, cancel reference numeral "2" and substitute therefor ---l--- line 52, cancel reference numeral "29" and substitute therefor ---l9--- Column 5, line 5, cancel "and causes oil to surge back to the lower portion of" line 6, cancel "the housing 4" line ll, cancel "vent" second occurrence and substitute therefor ---event-- Signed and sealed this 28th day of December 1 971 (SEAL) Attest:

EDWARD M.F'LETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORM PC4650 ($69) USCOMM-DC 60376-P69 US. GOVERNMENT PRINTING DFFICE: I969 O-366-33l 

1. In liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed, a base assembly having a bore communicating with the user assembly, socket means associated with the base assembly and communicating with the bore in said assembly, a reservoir assembly containing the liquid supply and having outlet means, said reservoir assembly being adapted for disposal in the socket means with the outlet means in communication with said socket means and hence with said user assembly, said reservoir assembly outlet means establishing the desired constant liquid level in said user assembly, vent means in communication with said reservoir assembly outlet means to vent the reservoir assembly through said outlet means to thereby restore the desired liquid level as liquid is consumed by the user assembly, and valve means for the reservoir assembly and the base assembly, the respective valve means being adapted to close when the reservoir assembly is removed from the socket means to prevent liquid flow from the reservoir assembly and user assembly and said respective valve means being adapted to open in response to a reassembly of the reservoir assembly into the socket means.
 2. The invention as set forth in claim 1 wherein the valve means for the base assembly is a ball check valve disposed in the bore of the base assembly with the valve seat adjacent to the socket means, the ball upon closure of the check valve being adapted to rest on the valve seat and project into the socket means, said reservoir assembly including means engageable with the ball of the check valve to unseat the ball and open the valve when the reservoir assembly is disposed in the socket means.
 3. The invention as set forth in claim 1 wherein the socket means is disposed in the base assembly and the base assembly bore is generally horizontal and extends radially from said socket means.
 4. The invention as set forth in claim 3 wherein the valve means is disposed in the base assembly and the base assembly bore is generally horizontal and eXtends radially from said socket means.
 5. The invention as set forth in claim 3 wherein the vent means comprises a generally vertically disposed tubular member secured to the base assembly and opening downwardly therefrom and extending upwardly generally coaxially through the socket means.
 6. The invention as set forth in claim 5 wherein the lower end of the venting tubular member is cut on a bias to provide an enlarged opening.
 7. The invention as set forth in claim 1 wherein the reservoir assembly includes a cover assembly which is removable to fill the reservoir assembly.
 8. The invention as set forth in claim 7 wherein the cover assembly for the reservoir assembly includes a body member of which at least the lower portion is adapted to be received within the socket means associated with the base assembly.
 9. The invention as set forth in claim 8 wherein the body member is slidably disposed within the socket means.
 10. The invention as set forth in claim 8 wherein the body member is threadedly engaged within the socket means.
 11. In liquid supply means for maintaining a relatively constant level of liquid in a user assembly wherein the liquid is consumed, a base assembly having a bore communicating with the user assembly, socket means in the base assembly and communicating with the bore in said assembly, a reservoir assembly containing the liquid supply, a removable cover assembly on said reservoir assembly, a body member carried by the cover assembly with at least the lower portion of said body member being adapted for disposal within the base assembly socket means, said body member being provided with a stepped bore with the smaller bore portion adjacent to the lower end thereof and an enlarged upper bore portion opening into the reservoir assembly, a tubular member secured in the smaller bore portion of the body member and extending upwardly through the enlarged bore portion, the bore of said tubular member communicating with said socket means and hence with the user assembly when the reservoir assembly is disposed in the socket means, outlet means in said tubular member placing the bore thereof in communication with the enlarged bore portion of the body member and hence with the interior of the reservoir assembly, a tubular valve member closed at the upper end thereof and slidably disposed on said tubular member for movement between an outlet means open position and an outlet means closure position, vent means in communication with said reservoir assembly outlet means for venting the reservoir assembly, abutment means associated with the base assembly and extending through the bore of the reservoir assembly tubular member and engaged by the closed end of the valve member to maintain the valve member in the outlet means open position when the reservoir assembly is disposed in the base assembly socket means, and means to bias the valve member downwardly to the outlet means closure position when the reservoir assembly is removed from the base assembly socket means.
 12. The invention as set forth in claim 11 wherein an annular shoulder is provided intermediate the stepped bore portions of the body member, said shoulder being engageable by the valve member in the outlet means closure position of said member.
 13. The invention as set forth in claim 12 wherein the tubular member outlet means comprises a plurality of circumferentially spaced generally rectangular slots which extend upwardly from the annular shoulder in the bore of said body member.
 14. The invention as set forth in claim 13 wherein the rectangular slots are of a width generally of an order of one-eighth inch to regulate the size of the venting air bubbles entering the reservoir assembly as liquid is consumed in the user assembly to thereby maintain the liquid level in the user assembly generally constant within relatively narrow limits.
 15. The invention as set forth in claim 13 wherein the vent means comprise a vertical tube secured to the base assembly and which opens downwardly bEneath the base assembly, said vent tube extending upwardly generally coaxially through said socket means and the bore of the tubular member, the upper end of said vent tube forming the abutment means engaged by the closed end of the valve member when the reservoir assembly is disposed in the base assembly socket means to maintain the valve member in spaced relation from the body member shoulder and thereby open at least some portion of the rectangular outlet slots.
 16. The invention as set forth in claim 15 wherein a threaded member is engageable within the upper end of the vent tube to form the abutment means engageable by the closed end of the valve member when the reservoir assembly is disposed in the base assembly socket means, said threaded member being vertically adjustable to vary the outlet slot openings and correspondingly vary the liquid level in the user assembly.
 17. The invention as set forth in claim 11 wherein check valve means are disposed in the bore of the base assembly and is adapted to close to preclude liquid flow from the user assembly when the reservoir assembly is removed from the base assembly socket means, said check valve means being adapted to open in response to a reassembly of the reservoir assembly into the socket means. 